Scaffolding-machine



F. PETERSON.

SCAFFOLDING MACHINE.

APPLICATION FILED MAY 12, 1920.

Patented Dec. 28, 1920.

3 0 KW I. f 0 MW #4. W 6/. U 4 Z I w an w a Z1 0. mg .4 W R 4 m L A H w w a 3, w v 4 3 a n v E 4 UNITED STATES PATENT OFFICE.

FRANK PETERSON, OF NEW YORK, N. Y., ASSIGNOR TO AMERICAN SAFETY DEVICE (10., OF NEW YORK, N. Y.

SCAFFOLDING-MACHINE.

Specification of Letters Patent.

Patented Dec. 28, 1920.

Application filed May 12, 1920. Serial No. 380,789.

T 0 all whom it may concern:

Be 1t known that I, FRANK PETERSON, a citizen of the United States, and resident of the Bronx, county of Bronx, and city and ers ladders, scaffolds, or other such light scaffolding structure, although it will be understood that the same is adapted for use in other connections.

An object of the invention is to provide a machine which will be entirely reliablein its function of sustaining, raising and lowering 1 the scaffolding, and which may be operated conveniently, with safety, and rapidity, so that the workman will not lose a great deal of time from his work in manipulating the scaffolding.

I further propose to provide a machine which may, if desired, be operated from the ground to lower the scaffolding rapidly, or to raise it, if desired.

Other objects are to provide a machine so arranged relatively to the platform and the suspension cables, that the platform will be maintained in a relatively steady position.

With these and other objects in view, an embodiment of my invention is shown in the accompanying drawings, and this embodiment will be hereinafter more fully described with reference thereto, and the invention will be finally pointed out and claimed.

In the accompanying drawings:

Figure 1 is a side elevation, showing a painters ladder scaffolding employing a 'pairof machines according to the present embodiment of my invention.

Fig. 2 is an end view of one of the ma chines, showing its connection to the scaffolding, and,

Fig. 3 is a side elevation thereof,

Similar reference characters indicate corresponding parts throughout the several figures of the drawings.

Referring to the drawings, the embodiment of my invention, as shown therein, comprises a frame consisting of a pair of side pieces 10 and, 11, spaced and parallel to each other, being connected at their upper ends by a shaft 12 threaded at its project ing end portions, a sleeve 13 being mounted thereon between the side pieces and retaining nuts 14: and 15 being screwed upon said projecting ends. At their lower ends the pieces 10 and 11 are connected by a pair of spaced shafts 16 and 17, threaded at their ends, and having retaining nuts 18 screwed thereon. Pairs of sleeves 19 are mounted on the said shafts, and between these: sleeves there is held the upper portion of a dependlng hanger bracket 20, to which is connected by bolts 21 and 22 the looped end of the scaffolding iron 23, in whichthe ladder platform 24 is supported in the usual manner.

Intermediate the shafts 12 and 16 there is provided within the frame a shaft 25, cotterpinned at its projecting ends, and having mounted thereon a winding drum 26 upon which the suspension cable 27 is secured and wound, and which cable extends upwardly through a U-shaped guide member 28, slidably mounted on the sleeve 13, and having a grooved roller 29 rotatably mounted therein.

At the ends of the drum there are rigidly secured flange plates 30 and 31, the plate 30 having peripheral V-shaped teeth forming a star shaped gear; while the plate 31 is-provided with ratchet teeth having their holding faces disposed upwardlyfat the. side of the drum from which the cable extends upwardly. V

An escapement lever 32 is pivotally mounted upon the side piece 10 at 33, being provided with V-shaped teeth 34: and 35 at the respective sides of the pivot 33 adapted to be alternately vengaged with the teeth of the gear 30 upon oscillation of the lever, one

of the escapement teeth entering between the gear teeth before the other becomes entirely'disengaged. The handle portion 36 of the lever is drawn toward theframe by a spring 37 connected at its ends to lugs 38 and 39 respectively, on the frame and lever, and'normally and'yieldingly holding the tooth 35 engaged with the gear.

Between the ratchet plate 31 and the side piece 11 of the frame there is pivotallymounted upon the shaft 25 an elongated lever &0 weighted at one end, as at 41, the weighted end functioning to normally hold this end in lowered position, and the other end raised. At the spaced end there is provided a pivotally mounted pawl 42 engaging the holding faces of the ratchet teeth, a handle portion 43 thereon enabling the same to be manually disengaged, a stop pin 44 on the lever limiting the movement of the pawl in its disengaged position.

When it is desired to raise the scaffolding, the workman stands squarely in front of the machine, and preferably grips both ends of the lever 40, turning the same about the shaft 25 in an oscillatory manner, and upon each downward stroke of the unweighted end the drum is turned to wind the cable thereon. During this action the escapement lever is automatically released from the gear 30, but is constantly in a position to prevent retrograde movement of the drum, during the upward movement of the unweighted end of the lever 40. "When the lever 40 is released, the weighted end immediately and automatically returns it to its normal holding position, as indicated in Fig. 2, so that the danger of the workman carelessly forgetting to lock the machine is a condition impossible in the present device.

In order to lower the scaffold, the pawl 42 is disengaged from the ratchet gear and the lever 40 drawn downwardly and tied in a position so that the pawl will be free of the ratchet, and thereupon by operating the escapement lever 32 with a pumping action the escapement may be rapidly lowered.

It is sometimes desirable, especially when first rigging up a scaffolding, to raise or lower the same from the ground, and for this purpose a rope or cable 45 is connected to the end of the short arm of the escapement lever 32, and extends to the ground, and also a rope or cable 46 is connected to the upper end of the lever 40, being passed through an eyelet therein, and provided at its end with a loop 47. In order to raise the scaffolding from the ground the rope 46 is pulled, the weighted end 41 of the lever automatically returning the same to its normal position. The scaffolding is lowered by first disengaging the pawl 42 from the ratchet gear, and thereupon drawing downwardly upon the rope 45, the weight of the scaffolding causing the escapement mechanism to operate rapidly in lowering direction. By first engaging the loop 47 with the handle 43 of the pawl 42 the pawl may be disengaged, from the ground, by pulling downwardly on the rope 46, the loop freeing itself as the lever 40 is drawn downwardly into non-retaining position.

The machine, according to my invention, has the advantages of being compact and of simple construction, conveniently operated and entirely safe. The mounting of the machines withthe axes of the drums in alinement, and longitudinally of the scaffolding platform maintains the platform in a constantly level position transversely, preventing any danger of listing of the platform, due to change of the position of the suspension cable upon the winding drum.

I have illustrated and described a preferred and satisfactory embodiment of my invention, but it is obvious that changes may be made therein within the spirit and scope thereof, as defined in the appended claims.

I claim:

1. A scaffolding machine comprising a frame, a winding drum journaled in said frame, a ratchet gear on said drum, an escapement gear on said drum, a lever pivotally supported on said frame, a pawl on said lever engaging said ratchet gear, adapted to permit rotation of said drum in raising direction of said drum, and prevent rotation in lowering direction, a pivotally mounted escapement lever having a pair of teeth, each adapted to respectively engage said escapement gear as the other is disengaged, said escapement lever adapted to be oscillated to permit movement of said drum in lowering direction when said pawl is released from said ratchet gear, said firstmentioned lever adapted to be oscillated to rotate said drum in raising direction.

2. A scaffolding machine comprising a frame, a winding drum journaled in said frame, a ratchet gear on said drum, a lever pivotally mounted to swing about the axis of said drum, a pawl pivotally mounted upon one arm of said lever, and engaging said ratchet gear, the other arm of said lever being weighted to normally maintain said first-mentioned arm in raised position, said pawl adapted to permit rotation of said drum in raising direction of said drum, and prevent rotation in the lowering direction, 105 said lever adapted to be oscillated to rotate said drum in the raising direction, and means adapted to prevent rotation of said drum in lowering direction when said pawl is inoperative.

3. A scaffolding machine comprising a frame, a winding drum journaled in said frame, a ratchet gear on said drum, an escapement gear on said drum, a lever pivotally supported in said frame, a pawl on 115 said lever, engaging said ratchet gear, adapted to permit rotation of said drum in the raising direction of said drum, and to prevent rotation of said drum in the lowering direction, a pivotally mounted escape- 120 ment lever having a pair of teeth disposed respectively at each side of said pivot, and each adapted to respectively engage an escapement gear as the other is disengaged, means normally retaining one of said teeth 125 yieldably in engagement with said escapement gear, said escapement lever adapted to be operated to permit movement of said drum in the lowering direction when the pawl is released from said ratchet gear, said 130 first-mentioned lever adapted to be oscillated to rotate said drum in the raising direction.

4:. A scafiolding machine comprising a frame, a winding drum journaled in said frame, a ratchet gear on said drum, an escapement gear on said drum, a lever pivotally supported on said frame, a pawl on. said lever engaging said ratchet gear, adapted to permit rotation of said drum in the raising direction of said drum, and prevent rotation in the lowering direction, a pivotally mounted escapement lever having a pair of teeth, each adapted to respectively engage said escapement gear as the other is disengaged, said escapement lever adapted to be oscillated to permit movement of said drum in the lowering direction when said pawl is released from said ratchet gear, said first-mentioned lever adapted to be oscillated to rotate said drum in the raising direction, and means connected to said respective levers extending to the ground, and adapted to permit raising or lowering of said machine by operation from the ground. 5. A scaffolding machine comprising a frame, a winding drum journaled in said frame, an escapement gear rotatable with said drum, a pivotally mounted escapement lever having a pair of teeth, each adapted to respectively engage said escapement gear as the other is disengaged, said escapement lever adapted to be oscillated to permit movement of said drum in lowering direction, and means for rotating said drum in raising direction. r

In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

FRANK PETERSON. 

